Drugs targeting the HIV virus transcriptase or protease are used in highly active antiretroviral therapy (HAART) cocktails that have prolonged the lives of AIDS patients. Unfortunately, these drugs are associated with severe toxicities, unable to control viral replication in some patients, and are rendered in effective by viral drug resistance. The absolute requirement of the integrase enzyme for HIV replication, and the fact that it has no host cell counterpart, make it an attractive drug development target. The recent introduction of the integrase targeted drug raltegravir has validated this enzyme as a very promising HIV/AIDS therapeutic target. Our studies on small molecule inhibitors of HIV integrase with novel bioisosteric replacement of the beta-diketo acid motive have led to the identification of novel HIV integrase inhibitors with single digit micromolar potency. We propose to undertake lead optimization to increase the potency and assess their potential to treat HIV infection. We will combine medicinal chemistry with computer-aided drug design and biological testing for potency, selectivity and toxicity. An innovative integration of docking, molecular dynamics simulations, structure-based design, chemoinformatics, pharmacophore mapping and three dimensional quantitative structure-activity relationships (3D-QSAR), parallel combinatorial synthesis, bioassays using recombinant wild type and mutant HIV integrase variants, cell culture testing against viral replication including drug resistant isolates from AIDS patients, will be applied. HIV-1 infected human peripheral blood mononuclear cell (PBMC) cultures will be used to test the ability of compounds to block HIV replication. Toxicity of compounds will be tested using uninfected PBMCs as well as CEM leukemia and Vero cells to assess therapeutic index. The success of this project will provide novel "drug- like" integrase inhibitors as preclinical HIV/AIDS drug development candidates;and increase our knowledge in the design of novel HIV integrase targeted antiviral agents. PUBLIC HEALTH RELEVANCE: This grant proposal seeks to develop new compounds for inhibiting HIV integrase to treat AIDS. The PI has discovered potent integrase inhibitors. The objectives of the grant proposal are to optimize activity and test toxicity.